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Isla de Mona

Island

An uninhabited island west of Puerto Rico's main island, Isla de Mona is a government-protected nature reserve known for limestone caves, clear snorkeling waters, and endemic species. Access requires permits from Mayagüez; visitors are typically divers, researchers, and experienced campers.

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Isla de Mona essentials

Address: Isla de Mona, offshore from Mayagüez/Rincón, Puerto Rico
Admission: Access requires permit; historically landing fees for day trips and park fees apply. Overnight stays tightly regulated (permits from Puerto Rico Department of Natural and Environmental Resources).

About Isla de Mona

Isla de Mona is an uninhabited island in the Mona Passage, administratively part of the municipality of Mayagüez, Puerto Rico. It is a protected natural reserve known for its karst limestone landscape, caves and endemic wildlife.

The island attracts visitors for snorkeling and diving on surrounding reefs, cave exploration onshore, and wildlife observation, notably the endemic Mona ground iguana. Archaeological remains and Taino sites are also present and of interest to researchers and visitors with permits.

Mona has a record of pre-Columbian habitation and later small-scale use for navigation and resource extraction, but it remains largely undeveloped and is managed for conservation. Modern use is limited to research, regulated tourism and occasional temporary camps.

The island lies in the Mona Passage between Puerto Rico and the Dominican Republic and is administered from Mayagüez, Puerto Rico.

  • Access permits: Visits require prior permission from the Puerto Rican authorities; access is limited to protect wildlife and archaeological sites.
  • Natural highlights: The island is noted for limestone cliffs, extensive cave systems and endemic species such as the Mona iguana, making it a conservation area and popular diving destination.
When to Go

Best Time to Visit Isla de Mona

Best visited in the winter dry season for calmer seas and clearer water. Access is controlled year-round.

Dry season
December-April · 24-30°C
Calmer seas and better visibility for snorkeling and diving.
Shoulder season
May-June, October-November · 25-31°C
Hotter but often good diving; storm risk increases as the Atlantic hurricane season approaches.

Weather & Climate near Isla de Mona

Climate

Isla de Mona's climate is classified as Tropical Savanna - Tropical Savanna climate with consistently warm temperatures year-round. Temperatures range from 20°C to 33°C. Abundant rainfall (1031 mm/year), wettest in October.

Air Quality: AQI 30 Good
Temperature & Rainfall
Temperature Range
33°
Warmest Month
20°
Coldest Month
Monthly Conditions
Month Comfort Temp Feels Rain Sky Humidity Wind UV Daylight
January - 20° - 29° 25° 54 mm - - 4.4 m/s - -
February - 20° - 29° 25° 36 mm - - 4.6 m/s - -
March - 20° - 30° 25° 48 mm - - 4.6 m/s - -
April - 21° - 31° 26° 76 mm - - 4.5 m/s - -
May - 22° - 31° 27° 121 mm - - 4.1 m/s - -
June - 23° - 32° 28° 91 mm - - 4.3 m/s - -
July - 23° - 33° 28° 86 mm - - 4.6 m/s - -
August - 23° - 33° 28° 100 mm - - 4.3 m/s - -
September - 23° - 32° 28° 108 mm - - 3.8 m/s - -
October - 22° - 32° 27° 124 mm - - 3.6 m/s - -
November - 22° - 31° 26° 93 mm - - 4.0 m/s - -
December - 21° - 29° 25° 94 mm - - 4.4 m/s - -
Getting There & Around

How to Get to Isla de Mona

Boats depart from Mayagüez or Rincón; all trips require permits from the Puerto Rico Department of Natural and Environmental Resources (DNER) and coordination with licensed operators. The sea crossing can be rough; plan with an experienced operator and allow flexible timing for return due to weather.

Tips for Visiting Isla de Mona

  • Trips to Isla de Mona require an organized, licensed boat operator from Mayagüez or Rincón and a permit from Puerto Rico DNER - do not attempt the trip independently.
  • Bring snorkeling/diving gear if possible: the underwater walls and coral formations are the island's real draw.
  • Pack for a day on a remote, undeveloped island - shade is limited and there are no services except a small ranger station.